| 摘要 |
<p>PURPOSE:To attain operation start of a CPU normally by backing up a memory means with a battery power supply when a DC-DC converter is not operated and operating the CPU with a prescribed boosted voltage at its operation so as to prevent storage information from being lost. CONSTITUTION:A low voltage is applied from the battery power supply 1 to the CPU4 having a memory means when the DC-DC converter 2 is not operated so as to back up the memory means, and when a power switch 3 is thrown, a KON goes to a high level for a prescribed time through the operation of a capacitor C2, a voltage VDC of the CPU4 goes to a low level, transistors TR0, TR1 and the DC-DC converter 2 starts boosting the voltage of the battery power supply 1. A reset pulse is given to the CPU4 from a reset pulse generating circuit 5 during the rising of the boosted voltage so as to keep the operation in the halting state.</p> |
